Grease-cup



J. F. CRAVEN.

GREASE CUP.

APPLICATION FILED MAR 3|, 1911.

- Patented Sept. 7, 1920.

FIG.3

INVENTOR without change of cups, or parts.

UNITED STATES PATENT OFFICE.

JAMES F. CRAVEN, 0F PITTSBURGH, PENNSYLVANIA.-

GREASE-CUP.

Specification of Letters Patent.

Patented Sept. 7, 1920.

Application filed March 31, 1917. Serial No. 158,895.

To all whom it may concern:

Be it known that I, JAMES F. CRAVEN, a

resident of Pittsburgh in the county of .Allegheny and State of Pennsylvania, have v invented a new'and useful Improvement in Grease-Cups, of which the following is a specification.

This invention relates to automatic grease cups to be used for feeding a lubricant into machine bearings. More particularly it relates to a device of the class stated for automatically feeding the lubricant at a constant rate, and to means for controlling, the rate of feed by an adjustable air valve.

It is intended to provide a grease cup of a comparatively simple form, which may be readilyiilled and refilled, in which the rate of feed of the lubricant may be ad justed to an extreme degree of exactness,

and this rate of feed maintained throughout the emptying of the cup, and in which lubricants of varying degrees of viscosity, from very thick grease to light oil, may be fed Another object is to provide a grease cup having in effect a safety reservoir, retaining a small amount of lubricant, which will be fed to the bearing afterthe normal discharge of r the cup has ceased, upon the heating of the hearing by reason of friction resulting from the cessation of flow of the lubricating medium.

Other objects and advantages will more fully appear throughout the following specification.

Referring to the drawings, Figure 1 is a central vertical section through the completely assembled cup, showing the lubrlcant' expelling followerin withdrawn position,

as when the cup is full; Fig. 2 is a similar view showing the parts in relative position after the contents of the cup havebeen discharged; and Fig. 3 is an enlarged partial.

section showing details of the air valve for controlling the rate of feed of the cup.

For the lubrication of machine bearings,

which are in more or less constant use, and particularly for bearings which are themselves on moving partsand therefore not readily accessible to the operator in charge of the machinery, receptacles for lubricants have been provided, the lubricants being retained in a'chamber under pressure sufficient to force them into the bear ngs, and

springs provided to exert pressure onthe contents of the cup to insure a more or less vices of the character referred to.

The present invention avoids these and other disadvantages and difficulties, by providing an air-tight grease cup which will automatically feed to the bearing to be lubricated, the rate offeed being entirely controlled by the passage of air into the cup through a valve which has a micrometer control. The lubricant can be expelled from the cup only so fast as air passes through the valve, and therefore the rate of feed is less dependent upon the force of the driving spring than in the prior devices, and is completely regulable in that the amount fed can be entirely controlled as to the maximum amount. of lubricant expelled in any given period. .By the particular controlling means of this invention it is possible to use lubricants varying in consistency from'a very thick pasty grease to a light oil, and to secure a regular andeven flow of lubricant, from exactly'similar cups, one of them containing heavy grease, the other a light oil.

Referring to the drawings, the grease cup comprises a casing'l, having exterior threads at its lower end engaging similar threads in a base member 2, which has'a taper bored portion 3, and central outlet 4:, through a threaded extension .5, which is adapted to be screwed into the bearing to be lubricated.

Between this threaded portion 5' and the tapered portion 3 is provided a shoulder 6,

which is either square, hexagonal, or of other suitable shape to be gripped by a wrench for securely fastening into the bearing. The casing 1 has a cylindrical bore 7 forming the main lubricant containing chamber, which is open at the bottom to the outlet through the base member .2. The upper end is closed by a wall 8, which has a central bore extending therethrough, this bore being surrounded by an exterior bushing 9, and a bushing 10 extending for'a" considerable distance inside thechamber 7', the 1 bore being continuous through the two projections and casing wall. Through this-bore in the top of the casing a stem 11 operates.

bore 15 of the stem. This portion 30 of the iiThe boresand stem are carefullymachined so as to form a close, accurate fit, not varying more than a few ten thousandths of an inch, .aati-thevmost, The upper end of the stem 11 loqzh as threads 12 thereon, and the lower end has a plurality otannular grooves 18 ex-'. L'tending. around it. These grooves are of such number and so .placedfand spaced on f the stem that. the uppermost one never passes 15 .out Tofth'ebore of the bushing in the ex- .treine downward-travel of the stem, for pur- -zposes more --fully explained hereinafter.'

f. The stemhas a central bore-14L, at its upper pend, a;smaller central bore-15 continuing from the larger bore andextendingnearly to the lower end;.ot' the stem, and connecting withthat-portiorifof thechamber 7 behind ether follower, below described, which portion "01? thechamber is'designated 7. 5 3 The lower end of the stem 'is riveted over Land rigidlylcarries a sheet metal member ,which is pressed to .fform aifollowerl7, extending across. the chamber 7,.and making a. close fit with the wall thereof by means of a I Q;flexible, wa.sher.:.member 18, carried by a vi ifia nge'19, at the, outer edge of said follower, .fiSRVllLbG apparent from an inspection of ,thevdrawings, and as is usual in such c'on- :str uction. Tiler-follower is "formed with a reentrantiportion comprising aninner wall 2Q,ian outerwall ,21,.and a connecting por-Q litionz22, the ffiange 19 being, turned over ...h m'..u1e edgeof. the wall. 21. Acoiled j -spring'23 surrounds the follower'inthe space 401: between thefwall 21 and the casing, having. .vgn'oneend bearing, against the endwall 8 of tithe-casing, and. the other end, clamping the' ,.',washer 18 ,against the fiange'19'of the follower. It will be noted that the inner wall 200i the tollowerhas a clearance space'be-f tween itand i the .outs'ide'of the bushing 10, a so, that. theair can pass freely from the paswsage 16 .into thespace 7 behind said follower.

, there is a beveled shoulder 2% at the junction Qbfthe larger bore 14, and the smalle'r bore'l5.

A knurled nut '25, engages the outer threads Qfsthe .st.em"11,-and is'fadapted to withdraw aid st m,van'd the attached follower upon being turned down on the stem in abutment therefrom.

V bore 140i thestem 11 is made with abitlrha ving 'a taper'ed point, so that to form a portion 28 of smaller diameter allowlng a surrounding-space, and near its lower end the valve member is still further reduced, forming a shoulder 29, and a portion 30, adapted to extend into the smaller valve member is very slightly tapered from theshoulder-29 to its end, so that a considerable travel of the valve member occurs for slight variation in the area of passage around this closure valve and the wall of bore15. i 7 Y Bythis construction the travel downward of the valve member gradually closes the borele, and the change in opening because of the tapered valve, is so very gradual as to allow an exceedingly fine adjustment in the passage. The tapered valve will contact [with the wall of the bore 15, only at the junction point of the two bores, and the first time'the valve is forced into position the contact point on the outer wall will be formed into an ei'lective valve seat, and thereafter there will be very little wear of the parts. I A locking nut 31 engaging the "threaded portion 26 of the valve member is provided, by which the valve may be securely fastenedin any desired position of adjustment It will be understood that the threaded engagement of'the valve member and theinterior of the follower stem is loose,

as'also the engagement'of the locking nut '31 with the valve member, so that air will readily pass through the opening formed by the-threads, andthe control ofthe passage of'air to the inside of the 'cup will depend entirely upon the relative position of the tapered valve portion'3O in the smaller bore of the follower. stern. The operation of :the device is as follows ffBy removing the casing 1 from the base 2," and withdrawingthe'follower 17 to the positionshown in Fig. 1,'the cup may be filled with the lubricant which is to be fed Then the casing is securely threaded into its base, and the'nut 25 turned back on the stem 11 to its uppermost position, as shown in Fi 2, thus allowing the full forceof'the coiled spring 17 to bear against the .follower to expel the grease from the 'cup into the bearing'to be lubricated. However, the follower, when the cup is filled with grease, makes an air-tight fit in the casing and the travel downward of the followertends to'create a vacuum iii-the space behind 1t,: 1nthe--casmg. This partial vacuum" can only be relieved by passage of air into the eXha'ustedspace through the bores 14% land 15, whichare controlled by the tapered valve 30. 'By experiment the valve is adjusted to exactly'the right point to perumit passage of air to the exhausted space, and consequently to permit the follower to "eXp'el'the" grease-fromrthe-cup, at the rate force air through the packing is also weak--- the stem and its gui l.

[ passage 0 T he coiled spring is a strong force throughout the entire travel of the follower,'and will not be a ppreciably weakas that member approaches the limit elling motion. Tiis'rerders the lat i of the follower in expelli the grease dependent exclusively on the 1 whicn air is supplied to the space behind it, l is absolutely cor rolled by the flit of the valve member rate movement of the fole, dent upon the supply of air to the space herebehind, it is evident that lubricants of varying de rees of VlSCOSlt" D Q t) be supplied regularly at a predeten l I mined of feed.

lle annular grooves '13 around the lower nd oft-he follower stem are filled with oil the stem is inserted through the guidoushing, and these grooves, with the I of the stem audits guiding bear- P sufficient to prevent the passage of any air into the space around the stem 11. The oilj'in the grooves 13, because of its aaillar attraction and resistance to distribution, acts as a packing, the efficiency ingto increase with the amount or air that is exerted thereon. This packill" is impo'rtant not only as prevening the p sage of air into the cup, but also allowing some variation in the machining of bore. of allowable variation makes quantity production by "machining possible. It will be oh rved that these grooves'are of such numand so situated that always at least onev is inside the bushing 20, as sho Fi 2, It will also be observed tl- )acling grooves isin operation to prevent f air around the follower stem, the is then at its weakest point, so that packing element becomes less resistant the spring creating the exhaust tending to enedin direct proportion, and the efficiency of the oint is consequently maintained throughout the entire travel of the followeri in the casing.

The form into which the metal follower is pressed, besidesproviding for the least practicable space behind the follower, provides an annular open recess therein, which will retain a certain amount of the lubricant, which cannot be expelled by travel of the follower to its lower limit. Should the cup not be relilled at the end of its expelling v be used in the same cup, and that they The amount the reserve will furnish a safeguard,

a nting material injury to the bearing du a considerable space of time in which. the operator will have occasion to observe that the cup has been emptied, and know that itshould be refilled.

hind the follower, and a valve to regulate the rate at which airis admitted through said passage.

2. An automatic grease cup comprising a casing, a driven follower therein, a stem on the follow r extending through a passage in the end of the casing,an air passage through the stem to the interior of the casing behind the follower, and an adjustable valve controlling said air passage.

A rease cup comprising a casing, a driven rollower therein, a stem on the follower extending through a passage in the end of thecasing and having a lubricant packed it therein, an air'passage through the stem to the interior of the casing behind the follower, and a valve controlling said air passage.

i. A grease cup comprising a lubricantretaining casing, a follower therein making air-tight engagement therewith, a spring behind the follower, a passage through the casing behind the follower, an adjustable valve controlling the passage, and means to lock the valve in adjusted position.

v 5. A, grease cup comprising a lubricantretaining casing, a follower therein making airtight engagement therewith, means to drive the follower through the cup, an air passage through the casing behind the follower, an adjustable valve controlling said passage, and means to lock the valve in adjusted position.

GIAn automatic grease cup comprising a.

casing, a follower therein adapted to expel grease therefrom, a stem on the follower extending through a wall of the casing and having an air-tight lit therewith, an air passage through the stem to the interior of the casing behind the follower, a valve controlling said air passage, and exterior means engaging said stem to withdraw the follower against the driving means.

7. An automatic grease cup comprising a casing, a driven follower therein, a stem on said follower extending through a wall of the casing and threaded on its outer end, a nut engaging said threaded stem and abutting the casing to withdraw the follower against the pressure of the driving means, an air passage through the stem to the interior of the casing behind the follower, and a valve controlling said air passage.

8. An automatic grease cup comprising an air-tight lubricant-retaining casing, a driven follower therein adapted to expel grease therefrom, an air passage into the casing behind the follpwer, means for controlling said the one an air passage comprising a tapered valve adapted to fit into the passage, means to adjust the valve, and means to lock the valve in adj ust- Y .ed position. 7

9. An automatic grease cup comprising anair.-, tight lubricant-retaining casing, a driven follower adapted to expel the contents of 1 passage leading into the easing behind thefollower, athreaded valve vmember controlling said passage by means of a: tapered end thereon, and a locking nut {for retaining the valve in adjusted position.

10. A grease cup comprising a base memc ber adapted to screw into a bearing to be ylubricated, casing open at one end and adapted at the open end to screw into the base member, driven follower in the casing adapted to expel a lubricant from the cup,

1 a stemon the follower extending through a passage in the end of the casing, an air passage through the stem to the interior of the casing behind the follower, an ad ustable 1 valve member controlling said air passage,

screw into the base member and form a greasecup,a follower in the cup, a spring to drive the follower to expel the contents of the cup, a stem fixed on the follower and extending through a wall of the cup and mak- 31ng an air-tight fit therewith, an air passage :through the stem, a valve controlling sald 7 air passage, means to adjustthe valve and to lock it into adj usted-position,and exterior means to withdraw the follower against oressureof the drivin s rin A 12. An automatic grea'secup comprising I -bore through the casing for the follower stem, and annular oil-retaining grooves on a base, member adapted to screw into the bearing tobe lubricated, a cup-shaped casmember, and a driven follower adapted to expel the contents of the cup-through the :basemember, said-follower being formed with a reentrant, annular recess therein :ing adaptedcto be screwed into the base 7 uadapted to retain a reserve supply of lubricant after the follower has reached the limit of its expelling movement.

tending through a bore in the casing wall and making an air-tight fit therewith, a central bore 1n the stem, a smaller central bore extending beyond the first named bore and having an opening extending to the interior of the casing behind the follower, a threaded valve member in the larger bore of the stemvhaving a tapered end adapted to extend into the smaller bore and to seat on the shoulder formed by the junction of the two bores in the stem, and means to lock the valve member in position.

14. In an automatic grease cup comprising a casing, a driven follower therein making air-tight engagement therewith, and a stem on the follower extending through the casing wall, the combination of a guiding bore for the stem, and annular grooves on the stem adapted to be filled with oil to make an air-tight packing between the stem and its guiding bore. 7

15. In an automatic grease cup comprising an air-tight casing having a driven follower therein adapted to expel the contents, the combination of a cylindrical stem fixed on the follower, a guiding bore through the casing for said stem, and annular grooves on the stem adapted to retain asemi-liquid packing element toprevent passage of air through said bore around said stem.

16. In an automatic grease cup comprising an air-tight casing having a follower therein and means to drive the follower to expel the contents of the cup, the combination of a stem fixed on the follower having a central bore therethrough to admit air to the casing behind the follower, and a valve controlling said passage, the combination of a guiding the stem adapted in cooperation with the guiding bore therefor to prevent the passage of air around the stem into the casing.

In testimony whereof I have hereunto set my hand. 7

JAMES F. CRAVEN. W'itness: G. H. Lnnnsorm. 

